Ours are back to back and I wouldnt want it any other way. DD6 and DS4 are 16 months apart and DS4 and DD3 are 18 months apart. We got in and out of the baby phase relatively quickly. Sure it was hard sometimes, but we just went with it. We are both very relaxed parents though. We also practice Attachment Parenting which in my eyes makes things easier. They were also BFed through my next pregnancy. I did wean DD3 "early" at 14 months as I had to go through IVF for my 4th pregnancy and did not want her exposed to the added horomones that are necessary for IVF.
She may act like a 3 year old, or maybe like a 2 year old. but in my eyes that shouldnt make much of a difference.
ETA: That may have been confusing. I am a surrogate and did have a 4th child a year ago, but she is not mine.
I have just heard some things about how 3 years is sooo much better than 2 years, or about how much they can understand at certain ages and how jealous toddlers act depending on their age. So I thought it might make a difference.
We also AP and I think it has helped us with preventing tantrums / melt-downs with DD, but it can be draining at times for sure. I have heard some moms lose their milk during pregnancy, so I was worried about that.
Are you saying yours are, or that you think that is a good interval in general?
